NEUROLOGIST, psychiatrist, entomologist, eugenist, temperance and penal reform advocate, Auguste Henri Forel was born a century ago, on September 1, 1848, at Morges, Canton Vaud, in Switzerland. His childhood studies of ants culminated in the publication, at the age of twenty-six, of "Les Fourmis de la Suisse", of which Darwin confessed that seldom in his life had he been more interested by any book. Studying medicine at Zurich, Forel specialized in psychiatry and was appointed professor of psychiatry in the University and director of the Insane Hospital. The more important works of this indefatigable and versatile man include "Der Hypnotismus und die Suggestive Psychotherapie"(1889), "Hygiene der Nerven und, des Geistes"(1903) and "Die Sexuelle Frage"(1905). The last was translated into sixteen languages, and the year of his death witnessed the publication of a sixteenth edition. It was described by Havelock Ellis as "without doubt the most comprehensive, and taking into account its manysidedness, perhaps the ablest work which has yet appeared on the sex question". When he was fifty, Forel gave up teaching and devoted himself to the pursuit of his bewildering variety of interests. In 1912 he had a stroke, which resulted in permanent paralysis of his right hand. To the literature of autopathography he contributed an interesting account of his dysphasia in the Journal für Psychologie und Neurologie, of which he was founder and editor. His autobiography "Out of My Life and Work" (English translation, 1937) is a frank and fascinating selfportrait of one of the most picturesque scientific figures of modern times. He died in 1931.